Printed circuit boards (PCBs) are commonly provided with terminals which serve as means for making electrical connections between the circuits of the PCB and other electrical components such as cables or other PCBs. To ensure a high quality electrical contact between the PCB circuits and the terminals, solder is often used to connect the two. In addition to providing electrical contact between the PCB and other electrical components, terminals are often subjected to physical stresses caused by relative movement between the PCB and the connecting component. Such relative movement can result from the act of connecting or disconnecting the PCB from the other component, by rough handling or vibration experienced during use, or by thermal expansion of the terminals themselves. If the physical stresses experienced by a terminal are applied to the soldered connection between the terminal and the PCB circuit, cracks may develop in the soldered connection, resulting in poor electrical continuity, physical weakening, and eventually complete failure.
To deal with the above described problem, some prior PCB terminals have included a connector housing which surrounds the terminals themselves and carries most of the physical loads that would otherwise be borne by the terminals. Such a housing, typically made from a plastic material, is attached to the PCB independently from the electrical connection of the terminals by screws, rivets or some other rigid fastening means. The component to be connected with the PCB features a mating connector which includes electrical contacts compatible with the PCB terminals. The mating connector rigidly engages the connector housing when electrical contact is made between the terminals and the contacts, such that physical loads caused by relative movement of the PCB and the other component is borne by the connector housing and the terminals themselves are substantially isolated from the loading. Thermal expansion and contraction of the metallic terminals takes place within the surrounding connector housing so that much lower loads are generated than would occur if the terminals served as the load bearing portion of the connection. This type of connection assembly entails the added cost and complexity of manufacturing the connector housing, assembling it with the terminals, and attaching it to the printed circuit board.
An alternative method of dealing with relative movement between a PCB and a connecting component is to allow the terminal to be the load-bearing component, but to make it flexible such that it will deflect when such relative movement occurs. The deflection of the terminal acts as a spring to absorb the loading rather than transmitting it to the soldered connections between the terminals and the PCB circuit. A terminal of this type is disclosed in Japanese Utility Model Unexamined Publication No. HEI-4-88666. While terminals of this type effectively absorb some of the loading caused by relative motion or thermal expansion and contraction, the fact that the only rigid connection between the terminal and the PCB is at the points where the terminal is soldered to the PCB circuit requires that all physical loads ultimately be transferred through those points. If the magnitude of the relative motion between the PCB and the mating electrical component is greater than the amount that can be absorbed by deflection of the terminal, stress is applied to the soldered connections between the PCB and the terminal, with the possible result of degradation or failure of the connections.